Image-forming optical system, illumination apparatus, and observation apparatus

Abstract

Provided is an image-forming optical system including: a plurality of image-forming lenses that form a final image and at least one intermediate image; and a wavefront disturbing device and a wavefront restoring device that are disposed at positions having any of the intermediate images formed by the plurality of image-forming lenses therebetween and that apply phase modulation to the wavefront of light coming from an object. The wavefront disturbing device and the wavefront restoring device have the same phase distribution including a wave-shaped phase-advancing region and phase-delaying region that are symmetrical to each other, and are paired such that light passes through the corresponding phase-advancing region and phase-delaying region having opposite wave shapes.

1 . An image-forming optical system comprising:
 a plurality of image-forming lenses that form a final image and at least one intermediate image; and   a first phase modulator and a second phase modulator that are disposed at positions having any of the intermediate images formed by the plurality of image-forming lenses therebetween and that apply phase modulation to the wavefront of light coming from an object,   wherein the first phase modulator and the second phase modulator have the same phase distribution including a wave-shaped phase-advancing region and phase-delaying region that are symmetrical to each other, and are paired such that light passes through the corresponding phase-advancing region and phase-delaying region having opposite wave shapes.   
     
     
         2 . The image-forming optical system according to  claim 1 , wherein the first phase modulator and the second phase modulator each include a plurality of pairs of the phase-advancing region and the phase-delaying region that are arranged periodically. 
     
     
         3 . The image-forming optical system according to  claim 1 , wherein the first phase modulator and the second phase modulator apply phase modulation to the wavefront by means of the surface shape of the optical medium. 
     
     
         4 . The image-forming optical system according to  claim 1 , wherein the first phase modulator and the second phase modulator apply phase modulation to the wavefront by means of the interface shapes of a plurality of optical media. 
     
     
         5 . The image-forming optical system according to  claim 1 , wherein the first phase modulator and the second phase modulator have one-dimensional phase distribution characteristics. 
     
     
         6 . The image-forming optical system according to  claim 1 , wherein the first phase modulator and the second phase modulator have two-dimensional phase distribution characteristics. 
     
     
         7 . An illumination apparatus comprising:
 the image-forming optical system according to  claim 1 ; and   a light source that is disposed on the object side of the image-forming optical system and that generates illumination light to be made to enter the image-forming optical system.   
     
     
         8 . An observation apparatus comprising:
 the image-forming optical system according to  claim 1 ; and   a photo-detector that is disposed on the final-image side of the image-forming optical system and that detects light emitted from an observation object.   
     
     
         9 . An observation apparatus comprising:
 the image-forming optical system according to  claim 1 ;   a light source that is disposed on the object side of the image-forming optical system and that generates illumination light to be made to enter the image-forming optical system; and   a photo-detector that is disposed on the final-image side of the image-forming optical system and that detects light emitted from an observation object.   
     
     
         10 . An observation apparatus comprising:
 the illumination apparatus according to  claim 7 ; and   a photo-detector that detects light emitted from an observation object illuminated with the illumination apparatus,   wherein the light source is a pulsed-laser light source.